This paper examines the use of a simple classroom activity, in which students are asked to take action representing either collusion or competition for extra credit to teach strategic thinking required in an oligopolistic market. We suggest that the classroom activity is first initiated prior to the teaching of oligopoly and then the instructor teaches oligopoly together with more enhanced classroom activities in accordance with a dynamics of the oligopolistic market. With this approach, the instructor can guide students toward strategic thinking by demonstrating how a student's incentives lead to specific actions within the experiment, which approximates a core trait of Cournot competition.